Automated motor adaptation
AssigneeDanfoss Power Electronics A/S
InventorsMark A. Bertolasi, Michael Harke, Charles J. Romenesko, Shaohua Suo
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Abstract
A method of determining electromagnetic characteristics of an asynchronous motor system is described. A motor system model is presented including a stator resistance, a transient inductance, a magnetizing inductance and a rotor resistance. A DC sequence is used to determine the stator resistance, a voltage pulse is used to determine the transient inductance, a binary injection frequency search algorithm is used to determine the magnetizing inductance, and an AC sine wave at slip frequency with DC offset is used to determine the rotor resistance.
Claims22
A method of operating an asynchronous motor system based on determined electromagnetic characteristics of the asynchronous motor system, wherein the electromagnetic characteristics include a transient inductance, the method comprising:
- determining the electromagnetic characteristics of the asynchronous motor system;
- and
- controlling, by a controller, the asynchronous motor system based on the determined electromagnetic characteristics;
- wherein the determining the electromagnetic characteristics comprises:
- applying a voltage pulse to the motor system;
- taking a plurality of samples of a rising portion of a current pulse generated in response to the voltage pulse;
- and
- using a non-linear curve fitting algorithm to determine the transient inductance of the motor system from said samples.
A method of operating an asynchronous motor system based on determined electromagnetic characteristics of the asynchronous motor system, wherein the electromagnetic characteristics include a magnetizing inductance, the method comprising:
- determining the electromagnetic characteristics of the asynchronous motor system;
- and
- controlling, by a controller, the asynchronous motor system based on the determined electromagnetic characteristics;
- wherein the determining the electromagnetic characteristics comprises:
- injecting a signal into the motor at a first frequency;
- determining the magnetizing inductance and flux in the motor at the first frequency;
- comparing the flux at the first frequency with an expected flux;
- adjusting the frequency of the injected current in the event that the flux is not sufficiently close to the expected flux;
- and
- using the magnetizing inductance measured when the flux is sufficiently close to the expected flux as the magnetizing inductance of the motor system.
Dependencies are inferred from the claim text.